Poor exercise choices will not only fall short of getting you desired results, but they can ultimately lead to a debilitating injury. It's a double whammy you want to avoid.

Here are five of the all-time worst exercises - and five super substitutes. Out with the bad, in with the good!

Standing Dumbbell Pec Flys

These exercises are performed in many body-sculpting classes and I've even seen personal trainers use them with their clients. They are supposed to work the chest muscles which are also known as your pectorals. The problem: they don't work the pecs at all!

In order for a move to be effective, it must oppose gravity. In this exercise, the motion is horizontal to the ground while gravity is, of course, vertical. All you end up with is a very inefficient way of isometrically work the front delts...

ABOUT BRAD: Brad Schoenfeld is one of America's leading fitness experts. He's the author of Sculpting Her Body Perfect, 28-Day Body Shapeover and the bestseller Look Great Naked. Schoenfeld is certified as a strength and conditioning specialist by the National Strength and Conditioning Association and as a personal trainer by both the American Council on Exercise and the Aerobics and Fitness Association of America. He's also been named "master trainer" by the International Association of Fitness Professionals. Check out his website at www.lookgreatnaked.com